It is customary in football training practice to present opposition to defensive linesman in the form of machines or devices simulating the opposing offensive line. The defensive linesman's primary purpose is to make his way through the offensive line seeking the ball carrier and either tackle the ball carrier or interfere with the ball carrier's attempt to pass the football. To this end devices have been made which present a static opposition to the defensive player such as a hard packed, sand or otherwise filled, canvas bag which the defensive player rushes and attempts to block out of the way with his shoulders or to run over the device.
Similarly there are devices consisting of static filled blocking dummies which may be sled mounted or spring mounted to permanent structures such that the defensive linesman can move the dummy only with a sufficiently large applied force.
It is presently popular for defensive football players to employ the so called "rip up" movement of their arm to move aside a blocking offensive linesman in order to maneuver their way past the offensive linesman and make contact with the ball carrier, or to be in position to block an attempted football pass. To accomplish this rip-up movement, the defensive player, moving from a two, three, or four point stance (two feet on the ground, two feet plus one hand touching the ground, or two feet plus both arms touching the ground), raises his arm up and across his body, the arm being bent at an approximate 90.degree. angle at the elbow. If the defensive player wishes to oppose an offensive player to his left, the defensive player raises his right arm to perform the rip-up movement. The player's first movement is to bring his arm (palm towards his body) to catch his opponent's helmet at the top of his arm, permitting the opponent's helmet to catch in the acute angle formed by his arm and forearm, and turn the opponent player's head away from the hole that the defensive player in attempting to create in the offensive line. While one arm is performing the rip-up movement, the other arm is out to the side helping the defensive player maintain his balance and to ward off any other players. Then with a short, quick step, the defensive player steps past his opponent player and into the hole that has been created by turning the offensive player away. The rip-up movement described is accomplished for two purposes, one is described above and two, as a protective measure to prevent the opposition player upon whom the movement was performed, from blocking the defensive player at his knee level.
The defensive player recovers after bringing his arm up and across to a two-point stance, low to the ground, and ready, if necessary, to perform the same rip-up movement operation upon an offensive linesman who perhaps has noticed his fellow player's situation and attempts to block the defensive linesman's rush through the line. The defensive linesman then may again continue with the second rip-up movement, utilizing the appropriate arm. Naturally, the offensive players do resist the rip-up movement by attempting to extricate their helmet from the defensive player's grasp.